A recombinant bacterial cell strain is disclosed. It comprises: a) a first vector comprising a fusion transgene encoding Ag85B-CFP10 fusion protein, the fusion transgene being operably linked to a promoter effective for expression of the Ag85B-CFP10 fusion protein and b) a second vector comprising a transgene encoding interleukin-12 (IL-12), the transgene being operably linked to a promoter effective for expression of the IL-12 protein. A method of inhibiting intracellular growth of Mycobacterium in a subject is also disclosed.